Intel Optane Persistent Memory Looking at Green Apache Pass DIMMs

Recently, we published A Close Look at Intel Optane DC Persistent Memory Modules using the blue OPM modules. After that article, a number of comments came in that the Apache Pass (codename for OPM) modules that have been published thus far have all been green, like most DDR4 DIMMs. We managed to get a hold of some of the green modules, just to show a quick comparison point. Here are two 512GB engineering sample Intel Optane DC Persistent memory DIMMs that we had hands-on time with when the brand was announced in May.

The Intel Optane Persistent Memory DIMMs are set to fill DIMM slots of Intel Cascade Lake generation CPUs as that product goes GA in a few months. We fully expect that only top end SKUs, like the Intel Xeon Platinum line, will support Intel Optane DC Persistent Memory as was the plan when the DIMMs were supposed to arrive with Skylake-SP.

Still, since we already had a green Apache Pass module in the lab, we figured it may be time to see if there are any design differences.

Intel Optane DC Persistent Memory Evolution

Here is a view of the blue PCB Intel Optane DC Persistent Memory DIMM along with the green Apache Pass module. You will see that we had to pull a firmware sticker to get front and back views. We also taped the green module in green electrical tape just to keep descriptions easy.

Intel Optane DC Persistent Memory Blue V Green AEP

Here you can see the other side, and a lot of heavy taping. The rightmost label on the green Apache Pass module is the same that you have seen in previous shots starting with “AEP” which is the codename prefix for Apache Pass as we use SKL for Skylake.

Intel Optane DC Persistent Memory Blue V Green 2

Opening the module was the same as we saw in our previous video:

We are not going to go into that again. Instead, here is a look at the Intel controller side of the green Apache Pass 128GB module:

Intel Optane DC Persistent Memory Green Controller Side

You can see six packages, and the LRDIMM buffers like we saw in the blue version. There is a Winbond IC that is not present on the green Apache Pass DIMM’s left side. The left area that is located under the heat spreader cutout is also different on the green PCB beyond just the Winbond move.

Here is the SK.Hynix DRAM side of the PCB where another five 3D XPoint packages are found. You can see a number of changes:

Intel Optane DC Persistent Memory Green DRAM Side

One of the biggest changes is that the Winbond IC has swapped sides. In the blue Intel Optane Persistent Memory DIMM, it was on the controller side. On the Green Apache Pass DIMM, it is on the DRAM side. There are three packages that we could not read markings on that had between 5 and 8 pins on each side that were moved along with the Winbond chip.

Here is the DRAM side of the blue OPM module for your comparison.

Intel Optane V DDR4 DIMM Underneath Controller Side 2

You can also see that the IC to the right has moved and is further right on the green module versus the blue. When the Winbond package moved to the other side, this chip was able to move left more towards the 3D XPoint packages.

Intel Optane V DDR4 DIMM Underneath Controller Side

Final Words

Again, we took these apart so you do not have to. We simply wanted to show the difference between the two modules since most have seen pictures of green Apache Pass samples in the past. To learn more about why Intel Optane DC Persistent Memory is a highly anticipated product, see our piece A Close Look at Intel Optane DC Persistent Memory Modules..

Patrick has been running STH since 2009 and covers a wide variety of SME, SMB, and SOHO IT topics. Patrick is a consultant in the technology industry and has worked with numerous large hardware and storage vendors in the Silicon Valley. The goal of STH is simply to help users find some information about server, storage and networking, building blocks. If you have any helpful information please feel free to post on the forums.